In that case, I'm sorry you have to go through that. Unfortunately, in my experience, those are hard minds to change. I had no choice but to let him go and try to figure it out. I was so heart broken I didn't even date for seven months, but that is when I met my husband. The guy showed up about two months into my new relationship and almost convinced me to break up with him, but I didn't because I knew it was his mistake for letting me go in the first place. Getting over something like that would be hard on a relationship anyway, if you guys ever got back together.
If you havn't already, I would tell him you want to be there for him, no matter what he's going through. But if he insists on ending it, just let him know that you wont let the breakup consume your life, and you will have to move on.
Like letagrlshow said, if it's truly love, there's a way to make it work. If he doesn't think so, maybe he's not worth it.